Underground pipe couplings for emergency repair during pipe breakage

ABSTRACT

The present invention relates to an underground pipe coupling for emergency repair during pipe breakage provided with a ball and socket coupler joint having ball joint (5) which is free to slide inside socket joint (3) fastened by means of ball joint backing ring (4) along with ‘O’ ring (7) positioned in between them. A pair of Grip cam mounting plate (1), with grip cam (6)/double grip cam (6a) is provided. Out of which, one connects at one end of the broken pipe and ball joint (5) and the other one connects the other end of the broken pipe and socket joint (3) in a watertight manner by means of a resilient sealing ring (2) placed in between each one of them. Grip cam rotates on an eccentric axis in an anti-clockwise direction and prevents decoupling of the pipe joint.

FIELD OF INVENTION

The invention relates to underground pipe couplings for emergency repair during pipe breakage. More particularly by introducing a ball and socket to mechanical coupler (connecting plane end pipe to plane end pipe)/flange adapter(plane end pipe to flange) technology, making it feasible with a grip cam arrangement which is pull out proof that can transfer the angular thrust to the pipe itself, while ball and socket joint gives flexibility in any desired degree. As there is no welding, gluing, nor thrust block preparation, comparing with the current practice, the down time of repair can be considerably reduced with an economic significance. The simplicity of the product gives technological advancement in repair jobs. Hence it is a reliable solution to attend an emergency underground pipe breakage.

BACKGROUND OF THE INVENTION

Pipe couplers are widely used in underground and above ground piping network to transport fluid medium viz. drinking water, sewerage etc. Due to alignment issues in various type of installations and changes in geological conditions, Seismic vibrations, thermal expansions, unforeseen loads on pipes (traffic, roots of trees, chamber settlement etc.) result in pipe breakage. Hence mechanical flexibility in couplers is of paramount importance in pipe construction industry.

PRIOR ART

Different methods of joint have been hitherto used for the repair of underground pipelines in an emergency situation in the industry. Some of the related prior art is mentioned here by way of reference.

U.S. Pat. No. 2,550,536 disclose flexible pipe connections and is particularly concerned with a ball and socket pipe joint.

U.S. Pat. No. 3,276,796 relates to pipe joints and couplings of the ball and socket type, and more particularly to an improved boltless, flexible joint for coupling the ball and bell ends of adjacent cast iron pipe sections to ether in a positively locked, leak-proof manner.

U.S. Pat. No. 5,624,206 A discloses an apparatus and method for supporting pipe main repair tools in an excavation while repairs are being made requires only exposure of the top surface of a buried main and utilizes an anchoring system installed.

U.S. Pat. No. 5,078,546 A relates to techniques for removal and replacement of underground pipelines, such as gas mains, service lines and the like.

U.S. Pat. No. 4,776,617 relates to a telescopic swivel pipe joint for coupling a pair of axially spaced pipes each having a connection end comprising a pair of joint connectors each connected to the connection end of a corresponding pipe and having a spherical bearing surface, a pair of main joint tubes each having a cylindrical portion and provided at one end thereof with an integral spherical ‘portion for slidable contact with the bearing surface of a corresponding joint connector, ‘and an auxiliary joint tube removably connected at both ends thereof to the respective cylindrical portions of the main joint tubes, wherein the auxiliary joint tube is telescopic in itself or telescopically fitted at one end thereof to the cylindrical portion of a corresponding main joint tube.

U.S. Pat. No. 2,475,834 discloses a flexible pipe Joint comprising of nested ball and socket type and is particularly useful in exhaust lines for internal combustion engine which are exposed to corrosive gas at high temperature.

CA 2176464 C teaches a system using an assembly for coupling coaxial pipes, such as flexible coaxial pipes, of the type used in environmentally conscious petroleum transfer systems.

While various types of pipe joints have been proposed heretofore, as can be seen from the prior art disclosures, many difficulties have been experienced in providing a joint which is truly leak-proof and which will withstand severe in-service load conditions resulting from external beam loading.

The present invention is envisaged to remove the disadvantages that have been found in the existing practice followed in the industry and in the prior art documents. Hence I have come up with state of the art underground pipe couplings for emergency repair during pipe breakage by my extensive R and D effort. Here one can have the mechanical flexibility to said underground pipe couplings up to 30 degree or above without sealing rubber deformation and the degree is determined by diameter of the ball used. This can have a global market and estimated to generate more than 5 million dollar per year according to a conservative estimate. The operational area of this application spans more than 150 countries and the end user can save significant amount in the overall repair job of underground pipe line installations. It has wider applications in infra structure development, Sewerage, storm water, irrigation lines, portable water networks, pumping stations, plant piping works, waste water treatment plant and pipe entry to underground chambers. The area of applicability includes new construction sites, especially earthquake prone areas.

OBJECTIVES OF THE PRESENT INVENTION

Therefore the main objective of the present invention is to provide a cost effective solution, but reliable joint for the broken underground pipe lines, in situ, in an emergency situation.

Another objective of the invention is to have most simple and fast method of joining the broken underground pipes in an emergency situation.

Yet another objective of the invention is to provide a joint in the broken underground pipe line network in an emergency situation which is having mechanical flexibility of 30 degree and more without sealing rubber deformation.

Still another objective of the invention is to serve as a multipurpose joint giving a reasonable flexibility matching to the pipe shape and provide a reliable sealing at the jointed portion.

One more objective of the invention is to use a type of joints in the pipe line network which is most suited in earth quake prone areas.

Another objective of the invention is a reliable pipe line joint which has universal application in sewerage, storm water, irrigation lines, and portable water networks.

Yet another objective is to have a pipe line joint which can be gainfully used in pumping stations, plant piping works and waste water treatment plant.

The above objectives of the present invention have been achieved, based on our extensive R&D work.

SUMMARY OF THE INVENTION

The present invention provides cost effective and reliable underground pipe couplings for emergency repair during pipe breakage. In the event of a pipe breakage, a conventional mechanical coupler or a flange adaptor with pipe seals are employed for joining the broken pipe. Here by introducing a ball and socket to mechanical coupler (connecting plane end pipe to plane end pipe)/flange adapter(plane end pipe to valve flange) technology, making it feasible with a grip cam arrangement which will transfer the angular thrust to the pipe itself, while ball and socket joint gives flexibility in any desired degree. As there is no welding, gluing, nor thrust block preparation as being done at present. The simplicity of the product gives technological advancement in repair jobs. Hence it is a reliable solution to attend an emergency underground pipe breakage.

As there is no welding, gluing, nor thrust block preparation, comparing with the current practice, the down time of repair can be considerably reduced with an economic significance. Hence it is a reliable solution to attend an emergency underground pipe breakage.

The pipe coupling assembly according to the present invention is comprising of: a) Grip cam mounting plate (1) consisting of a circular ring structure having the provision for mounting grip cam (6), on both two ends where the broken pipe has to be joined; b) grip cam (6) which is pivoted to the Grip cam mounting plate (1) that is capable of rotating and lock the pipe to prevent decoupling of the pipe joint; c) resilient sealing ring (2) placed in between Grip cam mounting plate (1) and socket joint (3) as well as Grip cam mounting plate (1) and ball joint (5); d) socket joint (3) that in conjunction with ball joint takes care of the flexibility requirement arised out the stress caused by the environmental factors; e) ball joint (5) which is free to slide inside socket joint (3) giving a mechanical flexibility to up to 30 degree and more based on the size of ball; f) ball joint backing ring (4) which serves to hold ball joint (5) in position by fastening to socket joint (3); and g) ‘0’ ring (7) for ensuring the proper sealing between ball joint backing ring (4) and the socket joint (3).

According to another embodiment under the invention, instead of single grip cam (6), there is provided double grip cam (6 a) that is capable of rotating and lock the pipe to prevent decoupling of the pipe joint especially in the case of large diameter pipe. Said double grip cam (6 a) is pivoted to Double grip cam mounting/holding block (70) which is assembled in between the modified grip cam mounting plate (1 a) and back plate (65) by means of threaded fasteners.

BRIEF DESCRIPTION OF DRAWING

These and other features, aspects and advantages of the present invention will become better understood when the detailed description is read with reference to the accompanying drawing.

FIG. 1: Underground pipe coupling for emergency repair during pipe breakage according to an embodiment under the invention.

FIG. 2: Underground pipe coupling assembly fitted to a broken pipe as part of emergency repair during pipe breakage according to an embodiment under the invention.

FIG. 3: Exploded view of pipe coupling assembly fitted to a broken pipe as part of emergency repair during pipe breakage shown in FIG. 2.

FIG. 4: Cross sectional view of the pipe coupling according to an embodiment under the invention shown in FIG. 1.

FIG. 5: Cross sectional view of the pipe coupling assembly fitted to a broken pipe line shown in FIG. 2.

FIGS. 6a and 6b : Front and back isometric view of the ‘socket joint’ of the pipe coupling assembly.

FIGS. 7a and 7b : Front and back isometric view of the ‘resilient sealing ring’ of the pipe coupling assembly.

FIGS. 8a and 8b : Front and back isometric view of the ‘ball joint’ of the pipe coupling assembly.

FIGS. 9a and 9b : Front and back isometric view of the ‘ball joint back ring’ of the pipe coupling assembly.

FIGS. 10a and 10b : Front and back isometric view of the ‘grip cam mounting plate’ of the pipe coupling assembly.

FIGS. 11a and 11b : Front and back isometric view of the ‘grip cam’ of the ‘grip cam mounting plate’ of the pipe coupling assembly.

FIG. 11c is the typical arrangement of lock pin when locked in a ‘grip cam’ and split pin.

FIGS. 12a, 12b and 12c : Different isometric view of the ‘grip cam’ assembled in the ‘grip cam mounting plate’ of the pipe coupling assembly.

FIG. 13a : Isometric view of the ‘grip cam mounting plate’ assembled with ‘grip cam’ mounted on the one part of the broken pipe to be repaired.

FIG. 13b : Cross sectional view of the pipe assembled with ‘grip cam mounting plate’ showing the direction of force applied when pipe moves away from the joint when the pressure inside the pipe increases.

FIG. 14a :Exploded view of the broken pipe assembled with ‘grip cam mounting plate’ assembled with ‘grip cam’, ‘resilient ring’ and ‘ball joint’.

FIG. 14b : Exploded view of the broken pipe assembled with ‘grip cam mounting plate’ assembled with ‘grip cam’, ‘resilient ring’ and ‘socket joint’.

FIG. 15: Isometric view of a portion of the pipe line network having two set of ‘underground pipe coupling’ according to an exemplary embodiment under the invention.

FIG. 16: Damaged/Leaking pipe requiring repair.

FIG. 17: After cutting away the damaged part of the pipe line from the damaged/leaking pipe shown in FIG. 16, leaving behind the other two ends of the pipe, which requires to be joined.

FIG. 18a ; FIG. 18b ; FIG. 18c ; FIG. 18d : Different stages during joining the two end of the pipes shown in FIG. 17, by means of the ‘ball and socket coupler with grip cam’ arrangement, according to the invention.

FIG. 19: Graph showing the chemical compatibility of the material used for the ‘Resilient sealing ring’ at different temperature.

FIG. 20: Underground pipe coupling assembly fitted to a broken pipe as part of emergency repair during pipe breakage according to another embodiment under the invention wherein double grip cam (6 a) is used for locking the pipe to prevent decoupling of the pipe joint especially in the case of large diameter pipe.

FIG. 21: Cross sectional view of the pipe coupling assembly having double grip cam (6 a) fitted to a broken pipe line shown in FIG. 20.

FIG. 22: Cross sectional view of the details marked as X in FIG. 21 showing ‘double grip cam” (6 a) pivoted to Double grip cam mounting/holding block (70) which is assembled in between the modified grip cam mounting plate (1 a) and back plate (65) by means of threaded fasteners.

FIG. 23a and FIG. 23b : Front and back isometric view of the ‘modified grip cam mounting plate’ (1 a) to which one end of the double grip cam assembly mechanism (64) is assembled, which is the part of the pipe coupling assembly.

FIG. 24a and FIG. 24b : Front and back isometric view of the ‘back plate (65) to which the other end of the double grip cam assembly mechanism (64) is assembled, which is the part of the pipe coupling assembly

FIG. 25: Isometric views of the double grip cam assembly mechanism (64)

FIG. 26: Exploded view of the double grip cam assembly mechanism (64) showing various components.

FIGS. 27a and 26b : Isometric views of the double grip cam mounting/holding block (70) pivoted with double grip cam (6 a) assembled in between the modified grip cam mounting plate (1 a) and back plate (65) by means of threaded fasteners.

Where in 1—Grip cam mounting plate; 1 a—Modified grip cam mounting plate; 2—Resilient sealing ring; 3—Socket joint; 4—Ball joint backing ring; 5—Ball joint; 6—Grip cam; 6 a—Double grip cam; 6 b—holes of the grip cam; 7—‘O’ ring; 8 a—First part of the broken pipe; 8 b—Second part of the broken pipe; 11—Bolting eye of grip cam mounting plate; 12—Grip cam holding jaw of grip cam mounting plate; 12 a—Hole for pivoting the pin of the grip cam; 13—Pipe admission path of grip cam mounting plate; 14—resilient ring pushing face of grip cam mounting plate; 15—Fastener (bolt); 31—resilient ring seat area for socket joint; 32—Bolting eye of the socket joint for grip cam mounting plate; 33—Bolting eye of the socket joint for ball joint backing ring; 34—O Ring grove of the socket joint (3); 35—Bell mouth area; 41—Bolting eye of ball joint back ring for socket joint; 51—Resilient ring seat area for ball Joint; 52—Bolting eye of ball joint for grip cam mounting plate; 53—Ball Inner Path for medium passage; 54—Ball joint sliding area; 61—Grip cam Mounting pin; 62—Lock pin; and 63—leaking portion of the pipe carrying the fluid; 64—double grip cam assembly mechanism; 65—the back plate; 66—Fastener for fixing the double mechanism assembled with grip cams to modified grip cam mounting plate; 66 a—Threaded hole for fastening the double mechanism assembled with grip cams to modified grip cam mounting plate; 67—Cam shaft for pivoting the double grip cam in the slot of double grip cam mounting/holding block from the side; 68—Grub screw; 68 a—Threaded hole for pilot loading the cams (6 a) from top of the Double grip cam mounting/holding block; 69—Fastener for fixing the double mechanism assembled with grip cams to back plate; 69 a—threaded hole for fastener for fixing the double mechanism assembly to back plate 70—Double grip cam mounting/holding block before assembly; 71—Rectangular slot provided in the double grip cam mounting/holding block (70) for fixing the double grip cams (6 a).

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an underground pipe coupling for emergency repair during pipe breakage. During the pipe breakage, the normal pattern seen is that the broken pipes will be misaligned (non-coaxial) i.e. centerline of both the pipes will not match and there will be an angle or an offset in the pipe.

In the normal circumstances in the event of a pipe breakage, a conventional mechanical coupler or a flange adaptor with pipe seals are employed for joining the broken pipe. Here the resilient sealing ring gives a slight flexibility of 3 degree basically based on the resilience property of the gasket used. Hence more number of couplers has to be employed to achieve the desired angle or the offset in the pipe.

However due to the change in the centerline there will be a resultant force and the vector will be not be in the center line which will result in decoupling when the pipe line is pressurized. To avoid this concrete block known as thrust blocks are used to arrest the movement to avoid decoupling.

In order to obviate said problems, I have introduced ball and socket coupler with grip cam arrangement for joining the pipe line especially when the breakage is underground. In other words by introducing a ball and socket to mechanical coupler (connecting plane end pipe to plane end pipe)/flange adapter(plane end pipe to flange) technology along with grip cam arrangement, while ball and socket joint gives flexibility in any desired degree, the grip cam transfers the angular thrust to the pipe itself As there is no welding, gluing, nor thrust block preparation, comparing with the current practice, the down time of repair can be considerably reduced with an economic significance. Hence it is a reliable solution to attend an emergency underground pipe breakage.

An underground pipe coupling for emergency repair during pipe breakage comprising of the following:

A pair of grip cam mounting plate (1), consisting of a circular ring structure having grip cam holding jaw (12) for mounting grip cam (6) as well as bolting eye (11) for connecting the ball joint (5)/socket joint (3). Out of which one connects one end of the broken pipe (8 a) and ball joint (5). The other one connects the other end of the broken pipe (8 b) and socket joint (3) in a watertight manner by means of a resilient sealing ring (2) each placed in between the grip cam mounting plate (1) and ball joint (5) as well as the grip cam mounting plate (1) and socket joint (3).

The grip cam (6) provided there in is capable of rotating on an eccentric axis of the Grip cam Mounting pin (61) mounted on grip cam holding jaw (12) of the grip cam mounting plate (1) and made to rotate in an anti-clockwise direction for locking the broken pipes to prevent decoupling of the pipe joint. Here the role of grip cam is multifunctional. It gives a reasonable flexibility to match to the pipeshape, even if it is oval, and gives uniform pressure on resilient sealing rings (2), as a number of such grip cams are provided as per the circumference of the pipe, thereby providing reliable sealing. The grip cam will transfer the angular or linear thrust created by the pressure of the fluid inside the pipe to the pipe itself while the ball and socket joint gives the flexibility in any desired degree.

The resilient sealing ring (2) used here is tapered along the circumference on outer periphery and is the mating part with the socket joint (3) as well as the ball joint (5). It is placed in between grip cam mounting plate (1) and socket joint (3) as well as between the grip cam mounting plate (1) and ball joint (5) to ensure proper water tight sealing.

Ball joint backing ring (4) provided there in is having about 8 or more numbers of bolting eye(41) for fastening the ball joint (5) and the socket joint (3). ‘O’ ring (7) placed in between ball joint backing ring (4) and the socket joint (3) ensures proper sealing. Socket joint (3) in conjunction with ball joint (5) takes care of the flexibility requirement arised out the stress caused by the environmental factors. Ball joint (5) is free to slide inside socket joint (3) and gives a mechanical flexibility up to 30 degree or above based on the size of ball.

FIG. 1 depicts pipe coupling according to the invention showing all the salient features of the invention while the FIG. 2 shows the broken pipe joined together by means of the pipe coupling according to the instant invention. Exploded view of the broken pipe joined together by means of the pipe coupling assembly according to the present invention is shown in FIG. 3. Cross sectional view of the pipe coupling assembly shown in FIG. 1 is illustrated in FIG. 4. Similarly cross sectional view of the broken pipe joined together by means of the pipe coupling according to the instant invention is illustrated in FIG. 5.

Referring to FIGS. 10a and 10b , grip cam mounting plate (1) is provided with 4 numbers of Bolting eyes (11) for fastening Ball Joint (5) as well as Socket Joint (3) using fasteners viz. bolt (15). The number of bolting eye (11) varies depending on the size of the coupler. Similarly the grip cam holding jaw (12) provided therein holds the grip cams (6) in position which is having a hole (12 a) where the grip cam gets mounted and is free to rotate as per the pipe moment in leaner direction which is detailed in FIG. 11a and FIG. 11 b.

FIG. 14a illustrates how the pipe is assembled with ball joint (5) through the resilient sealing ring (2) and grip cam mounting plate (1). Similarly FIG. 14b illustrates how the pipe is assembled with the socket joint (3) through the resilient sealing ring (2) and grip cam mounting plate (1).

Another purpose of the grip cam mounting plate (1) is to squeeze the resilient sealing ring (2) so as to make the pipe joint it leak proof.

One end of the pipe which is to be joined is inserted to the pipe admission path (13) of the grip cam mounting plate. The resilient sealing ring (2) is placed on the resilient ring pushing face (14) and when the fasteners are tightened Grip cam mounting plate (1) pushes the sealing ring (2) and gets closer to socket joint (3) and make it water tight.

Similarly the other end of the pipe which is to be joined is inserted to the pipe admission path (13) of the grip cam mounting plate. The resilient sealing ring (2) is placed on the resilient ring pushing face (14) and when the fasteners are tightened Grip cam mounting plate (1) pushes the sealing ring (2) and gets closer to ball joint (5) and make it water tight.

Front and back isometric view of the ‘socket joint’ (3) of the pipe coupling assembly is shown in FIGS. 6a and 6 b.

The resilient sealing ring (2) is tapered along the circumference on outer periphery as shown in FIGS. 7a and 7b which is the mating part with the socket joint (3) as well as ball joint (5). Resilient ring seat area (31) of the socket joint (3) is the area where the pipe to be joined enters. The fasteners are used to tighten between bolting eye (11) of the Grip cam mounting plate (1) and bolting eye (32) of the socket joint for fastening grip cam mounting plate. The tapered section of the resilience sealing (2) will get squeezed between the Grip cam mounting plate (1) and the resilient ring seat area of socket joint (31), there by sealing the gaps between Grip cam mounting plate (1), the socket joint (3) and the pipe and make it watertight. The bell mouth area (35) of the socket joint (3) is the entry point of Ball Joint sliding area (54). The ‘O’ ring grove (34) of the socket joint where ‘O’ ring (2) is so positioned that it enables the sealing between the socket bell mouth (35) and the ball joint (5).

One end of the socket joint (3) is provided with a ring structure (31 a) depending on the dia of the pipe to be joined having 4 or more bolting eye (32) and also having a resilient seating ring area (31) with diameter matching with that of the pipe to be joined so that minimum clearance is left which is sealed later on with the tapered portion of the resilient seating ring (2) when assembly is completed.

The other end of the ball joint is provided with a ring structure (35 a) matching with the maximum dia of the ball joint so that it can easily enter and having 8 or more bolting eye (33) depending on the size of the ball as well as internal ‘O’ ring grove (34) and in between is the bell mouth area (35) of the socket joint.

Tapered section of the resilient ring (2) passes through the clearance between the pipe and the socket joint as well as the ball joint. Due to its tapered cross section when the fasteners (15) are tightened, it squeezes through the clearance gap as the tightening increases, there by ensures the sealing. Lesser the shore hardness the sealing property increases. This is attained by maintaining the concentricity of the pipe with the guiding nature of the grip cam (6). The installation is co axial. As the sealing material is flexible there is only less rigidness in the assembly which allows an axial flexibility between pipe and the assembling arrangement. This makes it unique due to its flexibility compared to prior art couplings, flange or pipe joining arrangement. The disadvantages of the prior art coupling is that whenever the assembly gets shifted from its co axial center, the resilient sealing ring or gasket hitherto used which is made of rubber or similar material will be subjected to non-uniform stress pattern and cause gaps (clearance) between pipe and the assembly. Hence during long term usage it will result in leakage from the deflect area (Less stressed area of sealing ring). Here comes the relevance of the grip cam arrangement. The major advantage of this invention is that the sealing ring material selection has no restriction as it need not compensate for the piping flexibility.

According to instant invention the grip cam arrangement in combination with single ball and socket joint gives synergetic effect to the entire pipe line network and takes care of the flexibility requirement arised out the stress caused by the environmental factors and is able to achieve mechanical flexibility up to 30 degree and more, as against 3 to 6 degree of flexibility with the sealing ring used in conventional pipe joints. Hence in the present case resilient sealing ring (2) used can be made of graphite or SS 316 spiral wound, instead of flexible material like rubber.

The ball joint back ring shown in FIGS. 9a and 9b is a circular piece of steel ring with Bolting eye (41) having a curved profile matching with the curved surface of the ball joint so as slide over the ball joint outer surface (54) and allows sliding of the ball joint (5) concentric with the socket joint (3). Bolting eye (41) of the Ball joint backing ring (4) is fastened to the bolting eye (33) of the socket joint using fasteners (15) after placing the ‘0’ ring (2) in the ‘0’ ring grove (34) of the socket joint as shown in FIG. 3. Hence the ball joint backing ring (4) will serves to hold ball joint (5) in position.

Referring to the front and back isometric view of the ‘ball joint’ of the pipe coupling assembly shown in FIGS. 8a and 8b , the resilient ring seat area for ball joint (51) is the area where one end of the broken pipe enters. Fasteners are used to tighten between bolting eye (11) of the Grip cam mounting plate (1) and bolting eye (52) of the ball joint for fastening grip cam mounting plate.

One end of the ball joint (5) is provided with a ring structure (51 a) having 4 or more bolting eye (52) depending on the dia of the coupling and also have a resilient seating ring area (51) with diameter matching with that of the pipe to be joined so that minimum clearance is left which is sealed later on with the tapered portion of the resilient seating ring (2) when assembly is completed.

The other end of the ball joint is open and is meant for the fluid medium to pass having the matching diameter of the pipe which is the passage for the fluid medium (53), and in between is the spherical shaped area (54) over which bell mouth area (35) of the socket joint slides.

When these fasteners are tightened, the tapered section of the resilience sealing ring (2) will get squeezed between the Grip cam mounting plate (1) and the resilient ring seat area of ball joint (51), there by sealing the gaps between Grip cam mounting plate (1), the ball joint (3) and the pipe and make it watertight.

The ball joint sliding area (54) is the entry point to socket Joint (3) bell mouth. The ‘O’ Ring in grove (34) serves as the sealing between the socket bell mouth (35) and ball joint sliding area (54). When ball joint (5) is coupled with socket joint (3), it is free to slide inside socket giving a mechanical flexibility up to 30 degree or above based on the size of ball.

Front and back isometric view of the ‘grip cam mounting plate’ of the pipe coupling assembly is shown in FIGS. 10a and 10b . The Grip cam mounting plate consist of 4 numbers of Bolting eye (11) used to fasten the grip cam mounting plate (1) to a Ball Joint (5) or a Socket Joint (3) according to an exemplary embodiment under the invention. The number of bolts or fasteners used will vary depending on the size of the coupler. The grip cam holding jaw (12) holds the grip cams (6) in position by means of grip cam mounting pin (61).

FIG. 11a shows how the grip cam (6) is mounted on a pin (61). The grip cam is pivoted to the grip cam mounting pin in such a way that it is free to rotate its axis and is tightened once the pipe assembly is completed. The grip cam mounting pin is provided with lock pin (62) or known as split pin or cotter key which will lock grip cam mounting pin (61) in position with grip cam holding jaw (12).

FIG. 11c explains the typical locking details. However the grip cam is free to rotate as per the pipe moment in leaner direction which is detailed in FIGS. 11a and 11b . Different isometric view of the ‘grip cam’ assembled in the ‘grip cam mounting plate’ is shown in FIGS. 12a, 12b and 12 c.

The application of grip cam shown in FIGS. 11a and 11b is unique in the design of mechanical coupling to have an angular flexibility without limitations. In other words it enables a non-coaxial pipe to couple mechanically.

Isometric view of the ‘grip cam mounting plate’ assembled with ‘grip cam’ mounted on the broken pipe to be repaired is depicted in FIG. 13a . Working of a grip cam is illustrated in FIG. 13b . The grip cam (6) rotates on an eccentric axis on grip cam holding jaw (12) of the grip cam mounting plate (1). The grip cam is rotated anti-clock wise so that the pipe align to the center of the Grip cam mounting plate (1) and protects the possibility of co axial dis alignment of the pipe with the assembled part of assembly in the future. FIG. 13b shows how the ‘grip cam facilitates the tightening of the pipe joint in the event of the movement of pipe away from the joint due to increase in pressure inside the pipe and the thrust developed. The arrows in FIG. 13b show the direction of movement of the grip cam as well as the likely movement of the pipe.

The main advantage here is that resilient material with less shore hardness can be used for resilient sealing ring, as the grip cam act as guide to maintain the concentricity of the pipe. By using a less shore hardness resilient material even highly corroded Pipes can be sealed with less pipe surface preparation. Number of grip cam and the size of the cam vary with application (pipe pressure) and diameter of the pipe. Larger diameter pipes are always subjected to ovality in pipes and the grip cam can ensure uniform clearance between the pipe and sealing area of socket or ball joint.

In the case of non-coaxial installations, as the pressure inside the pipe increases, the thrust pushes the pipe away from coupler as shown by arrow in FIG. 13b . Any movement in the pipe away from coupler will cause the grip cam to rotate in circular direction in an anti-clock wise direction in line with pipe movement. This is because rolling friction on grip cam pin (61) is less compared to sliding friction between the contact area of grip cam (6) and pipe (8) on its axis enabling to give more rigid grip to the pipe. In other words as the pressure increases, the holding grip increase this feature make the coupling reliable to withstand leaner thermal expansions too without any breakage, depending on the clearance length of pipe provided after sealing ring during installation.

FIG. 14a shows the exploded view of the broken pipe assembled with ‘grip cam mounting plate’ assembled with ‘grip cam’, resilient ring and the ball joint. Whereas FIG. 14b shows exploded view of the broken pipe assembled with ‘grip cam mounting plate’ assembled with ‘grip cam’, resilient ring and the socket joint. A portion of the pipe line network having two set of ‘underground pipe coupling’ according to an exemplary embodiment under the invention is illustrated in FIG. 15 to understand how the instant invention is fruitfully deployed in a pipe line network.

Now steps involved in repairing the underground pipe which is broken as shown in FIG. 16 by means of the “pipe coupling” according to the present invention is given below:

-   -   Step 1 preparation of the damaged pipe for joining by cutting         away the damaged part and preparing first segment (8 a) as well         as the second segment (8 b) as shown in FIG. 17;     -   Step 2: Insertion of ball joint (5), resilient sealing ring (2),         grip cam mounting plate (1), and ball joint back ring(4) on the         first segment of the pipe (8 a) to be joined in the same order         as shown in FIG. 18 a;     -   Step 3: Insertion of socket joint (3) fixed with ‘o’ ring (7),         resilient sealing ring (2), and grip cam mounting plate (1), on         the second segment of the pipe (8 b) to be joined in the same         order as shown in FIG. 18 a;     -   Step 4: Coupling of ball joint (5) and socket joint (3) as shown         in FIG. 18 b;     -   Step 5: Clamping the ball joint (5) to socket joint(3) by means         of the ball joint back ring (4) and fastening by means of         fasteners (15) as shown in FIG. 18 c;     -   Step 6: Fastening the grip cam mounting plate (1) with ball         joint (5) by means of fasteners (15), with resilient sealing         ring (2) in between for the first segment part and tighten it to         ensure sealing as shown in FIG. 18 d;     -   Step 7: Fastening the grip cam mounting plate (1) with socket         joint (5), by means of fasteners (15), with resilient sealing         ring (2) in between for the second segment part and tighten it         to ensure sealing as shown in FIG. 18 d;     -   Step 8: Locking the grip cam (6) of the respective grip cam         mounting plate (1) both for the first segment part and the         second segment part as shown in FIG. 19a ; and     -   Step 9: Wrapping the coupler with sealing tape having anti         corrosion properties.

One such sealing tape used for protecting the ‘ball and socket coupler with grip cam arrangement’ is Denso Tape which is cold applied anti-corrosion and sealing tapes based on a synthetic fabric, impregnated and coated with a neutral petrolatum compound. Denso Tape manufactured under license by Winn & Coales (Denso) Limited.

According to another embodiment under the invention, instead of single grip cam (6), there is provided double grip cam (6 a) that is capable of rotating and locking the pipe to prevent decoupling of the pipe joint especially in the case of large diameter pipe is shown in FIG. 20. Said double grip cam (6 a) is pivoted to double grip cam mounting/holding block (70) which is assembled in between the modified grip cam mounting plate (1 a) and back plate (65) by means of threaded fasteners (66) and (69). Cross sectional view of the pipe coupling assembly having double grip cam (6 a) fitted to a broken pipe line shown in FIG. 21 for better clarity. Cross sectional view of the details marked as X in FIG. 21 is given in FIG. 22.

Front and back isometric view of the grip cam mounting plate (1 a) of the pipe coupling assembly are shown in FIGS. 23a and 23b . The modified grip cam mounting plate a circular ring structure consists of 4 numbers of Bolting eye (11) used to fasten the modified grip cam mounting plate (1 a) to a Ball Joint (5) or a Socket Joint (3). The number of bolts or fasteners used will vary depending on the size of the coupler. There is no grip cam holding jaw (12) in this embodiment under the invention, instead there is provided set of threaded holes (66 a) for fastening the double grip cam mounting/holding block (70). The rear side is having a taper section (14) so that when the fasteners are tightened between the bolting eyes of grip cam mounting plate (1 a) and bolting eye of the socket joint for grip cam mounting plate (32). Bolting eye of the socket joint (3) will squeezes the resilient sealing ring (2) between the gap of broken pipe (8 a) and socket joint (3) ensuring a tight water sealing. The same procedure is followed on the ball joint (5) and broken pipe (8 b) for the tight water sealing on the broken pipe (8 b) side. Rest of the functions is similar to the earlier version of grip cam mounting plate (1).

Two views of the Back Plate (65) are shown in FIG. 24a 24b . It is also is circular ring structure consists of 4 sets of threaded holes (66 a) for fastening the double grip cam mounting/holding block (70). It ensures double grip cam mounting/holding block (70) is position in between the Back Plate (65) and modified grip cam mounting plate(1 a).

Referring to FIG. 25 and FIG. 26, double grip cam mounting/holding block (70) is a solid steel block provided with a rectangular slot (71) to fix double grip cams (6 a). It is provided with a) a threaded hole (68 a) for inserting grub screw (68) from top of the block for pilot loading the cams(6 a) on the pipe; b) another two threaded hole on the flat side for fixing the grip cams (6 a) by means of cam shafts (67) on which cam (6) is free to rotate on an eccentric axis and made to rotate in an anti-clockwise direction for locking the broken pipes to prevent decoupling of the pipe joint; and c) one threaded hole (69 a) on one end for fixing the back plate (65) and another two threaded holes (66 a) on the other end of said block for fixing the modified grip cam mounting plate (1 a) by means of respective threaded fasteners (69 and 66), so that the double grip cam (6 a) is pivoted in the slot of double grip cam mounting/holding blockin such a way that it is free to rotate in its own as per the pipe moment in leaner direction. While the grip cam (6 a) is under operation there will be a force pushing the cam away from the pipe and lock the pipe to prevent decoupling of the pipe joint.

Isometric views of the Double grip cam mounting/holding block (70) pivoted with double grip cam (6 a) assembled in between the modified grip cam mounting plate (1 a) and back plate (65) by means of threaded fasteners is shown in FIGS. 27a and 26 b.

The method of assembling the double grip cam assembly mechanism (64) comprising of the following steps:

-   -   a) placing the double grip cam (6 a) in the Rectangular slot         (71) provided in the double grip cam mounting/holding block         (70);     -   b) inserting the Cam shaft (67) through the holes (67 a)         provided on the double grip cam mounting/holding block (70),         through the holes(6 b) in double grip cam (6 a) and lock the         shaft using the Circlip (67 b);     -   c) inserting the Grub screw (68) for pilot loading of the grip         cams (6 a) though the threaded holes (68 a) provided on the         double grip cam mounting/holding block (70).

Method of assembling the underground pipe coupling for emergency repair during pipe breakage when double grip cam (6 a) is used, instead of the grip cam (6), comprising of the following steps:

-   -   a) preparation of the damaged pipe for joining by cutting away         the damaged part and preparing first segment as well as the         second segment;     -   b) insertion of ball joint (5), resilient sealing ring (2), grip         cam mounting plate (1 a) assembled with, and ball joint back         ring(4) on the first segment of the pipe (8 a) to be joined in         the same order;     -   c) insertion of socket joint (3) fixed with ‘o’ ring (7),         resilient sealing ring (2), and grip cam mounting plate (1 a),         on the second segment of the pipe (8 b) to be joined in the same         order;     -   d) coupling of ball join (5) and socket joint (3);     -   e) clamping the ball joint (5) to socket joint(3) by means of         the ball joint back ring (4) and fastening by means of fasteners         (15);     -   f) fastening the grip cam mounting plate (1 a) with ball joint         (5) by means of fasteners (15), with resilient sealing ring (2)         in between for the first segment part (8 a) and tighten it to         ensure sealing;     -   g) fastening the grip cam mounting plate (1 a) with socket joint         (5), by means of fasteners (15), with resilient sealing ring (2)         in between for the second segment part (8 b) and tighten it to         ensure sealing;     -   h) assembling 4 nos of double grip cam assembly mechanism (64)         having the double grip cam (6 a) in between the modified grip         cam mounting plate (1 a) and back plate (65) by means of         fasteners (66) and (69)     -   i) locking the double grip cam (6 a) of the respective double         grip cam assembly mechanism (64) both for the first segment part         and the second segment part; and     -   j) wrapping the coupler with sealing tape having anti corrosion         properties.

Apart from the repair of broken pipes an extended usage of present invention is its uniqueness is its capability of handling various fluid transport mediums apart from water, waste water etc. It can be used for the coupling of pipe transporting different types of fluids at various temperature and pressure range. Selection criteria for material of construction of components used for the ‘ball and socket coupler with grip cam arrangement’ are as under.

For Grip cam mounting plate (1)/modifiedGrip cam mounting plate (1 a), Socket joint (3); Ball joint backing ring (4); Ball joint (5), and Black plate (65), material of construction will be determined based on the chemical property and the temperature of the fluid being carried i.e. based on chemical compatibility. It can be metallic or nonmetallice.g. PVC, PVDF, Ductile iron, Carbon steel, Stainless steel, titanium etc. Similarly the thickness of said part will be designed according to the fluid pressure. But for the grip cam the material has to be harder than that of the Pipe.

For resilient Sealing ring (2) material of construction will be determined by the fluid chemical property, temperature & pressure. Rubber based sealing rings (EPDM, Nitrile, PTFE etc.) is having limited capacity. It cannot withstand high temperature and pressure. According to our invention grip cam (6)/double grip cam (6 a) maintains the concentricity and the flexibility of the coupling is independent of resilient property of the sealing ring (2). There for to withstand higher temperature and pressure metallic or special sealing rings SS, Brass, graphite etc. can be used. It may not be out of place to mention here that if the prior art couplers use metallic sealing ring, then the coupler will be losing its flexibility when the fluid being transported is hot oil or gas having high temperature and pressure. Following Table 1 gives the material of construction of the Non-metallic sealing rings with its typical application along with temperature range.

TABLE 1 TYPICAL SEALING RING TEMPERATURE TYPICAL MATERIAL RANGE APPLICATIONS NBR −15° C. to 110° C. Cooling | LTHW | Oils NBR HT −10° C. to 135° C. Cooling | LT Hot Water | Oils HYDROGENATED NBR −10° C. to 160° C. HT Hot Water | Oils EPDM −25° C. to 150° C. HT Hot Water EPDM HT −10° C. to 160° C. HT Hot Water BUTYL −10° C. to 160° C. HT Oils & Solvents HYPALON −10° C. to 70° C.  Specialized Chemicals VITON ® (FKM) A/B/G  −5° C. to 130° C. HT Oils & Chemicals NEOPRENE −10° C. to 80° C.  Specialized Chemicals

Following Table 2 gives the material of construction of the metallic resilient sealing rings along with temperature range in which it can be used.

TABLE 2 Minimum Maximum Material ° F. ° C. ° F. ° C. Abbreviation 304 Stainless steel −320 −195 1400 760 304 316L Stainless steel −150 −100 1400 760 316L 317L04 Stainless steel 317L 321 Stainless steel −320 −195 1400 760 321 347 Stainless steel −320 −195 1700 925 347 Carbon Steel −40 −40 1000 540 CRS 20Cb-3 (Alloy 20) −300 −185 1400 760 A-20 HASTELLOY* B2 −300 −185 2000 1090 HAST B HASTELLOY* C276 −300 −185 2000 1090 HAST C INCOLY* 800 −150 −100 1600 870 IN 800 INCONEL* 600 −150 −100 2000 1090 INC 600 INCONEL* 750 −150 −100 2000 1090 INX MONEL* 400 −200 −130 1500 820 MON Nickel 200 −320 −195 1400 760 NI Titanium −320 −195 2000 1090 TI

Graph showing the chemical compatibility of the material used for Resilient sealing ring at different temperature is given in FIG. 21.

Following are the advantages of the present invention over the prior art invention.

-   -   1. Enhanced mechanical flexibility compared to mechanical         coupler and flange adaptors     -   2. No thrust block required in angular deflected areas     -   3. Uniform stress patterns on sealing ring enabling longer life         and quality of sealing     -   4. Self-aligning feature according to pipe orientations     -   5. Suitable for seismic vibrations (earthquake prone areas)     -   6. Pipe ovality compensation/correction feature

I have brought out the novel features of the invention by explaining some of the preferred embodiments under the invention, enabling those skilled in the art to understand and visualize the present invention. It is also to be understood that the invention is not limited in its application to the details set forth in the above description or as illustrated in the drawings. Although the invention has been described in considerable detail with reference to certain preferred embodiments thereof, various changes and modifications can be made without departing from the spirit and scope of the invention as described herein above and as defined by the appended claims. 

I claim: 1) An underground pipe coupling for emergency repair during pipe breakage provided with a ball and socket coupler joint wherein the ball joint (5) is free to slide inside socket joint (3) fastened by means of ball joint backing ring (4) along with ‘O’ ring (7) positioned in between them for ensuring the sealing between the ball and socket joint characterized in that said ball and socket coupler joint comprising of: a) a pair of Grip cam mounting plate (1), in the form of a circular ring structure having grip cam holding jaw (12) for mounting grip cam (6) as well as bolting eye (11) of the grip cam mounting plate (1) for connecting the ball joint (5) as well as socket joint (3), out of which one connects one end of the broken pipe part (8 a) and ball joint (5) and the other one connects the other end of the broken pipe part (8 b) and socket joint (3) in a watertight manner by means of a resilient sealing ring (2) placed in between each one of them; b) grip cam (6) which is capable of rotating on an eccentric axis of the Grip cam Mounting pin (61) mounted on grip cam holding jaw (12) of the grip cam mounting plate (1) and made to rotate in an anti-clockwise direction for locking the broken pipes to prevent decoupling of the pipe joint; and c) a pair of resilient sealing ring (2) which is tapered along the circumference on outer periphery is the mating part with the socket joint (3)/ball joint (5) and is placed in between Grip cam mounting plate (1) and socket joint (3) as well as Grip cam mounting plate (1) and ball joint (5) to ensure sealing. 2) The underground pipe coupling as claimed in claim 1, wherein grip cam mounting plate (1) is circular in shape and is meant for fastening the Ball Joint (5) or a Socket Joint (3) by means of fasteners and are provided with 4 or more number of bolting eye (11) and equal number of grip cam holding jaw (12) placed in between them and number of bolting eye (11) and grip cam holding jaw (12) depends on the size of the coupler used which in turn depends on the diameter of the pipe to be joined. 3) The underground pipe coupling as claimed in claim 1, wherein grip cam (6) is pivoted to the grip cam holding jaw (12) of the grip cam mounting plate (1) and holds in position by means of a grip cam pin (61) that is locked using lock pin (62) known as split pin or cotter key of in such a way that it is free to rotate in its own as per the pipe moment in leaner direction. 4) The underground pipe coupling as claimed in claim 1, wherein there are 4 or more numbers grip cam (6) which are capable of rotating on an eccentric axis of the Grip cam Mounting pin (61) mounted on grip cam holding jaw (12) of the grip cam mounting plate (1) and made to rotate in an anti-clockwise direction and locks the pipe to prevent decoupling of the pipe joint, so that the pipe to be joined align to the center of the Grip cam mounting plate (1) and protects the possibility of co axial dis-alignment of the pipe with the assembled part of assembly in the future. 5) The underground pipe coupling as claimed in claim 1, wherein a) one end of the ball joint (5) is provided with a ring structure (51 a) having 4 or more bolting eye (52) depending on the dia of the coupling and also having a resilient seating ring area (51) with diameter matching with that of the pipe to be joined so that minimum clearance is left which is sealed later on with the tapered portion of the resilient seating ring (2) when assembly is completed; b) the other end of the ball joint is open and is meant for the fluid medium to pass having the matching diameter of the pipe which is the passage for the fluid medium (53), and c) in between is the spherical shaped area (54) over which bell mouth area (35) of the socket joint slides. 6) The underground pipe coupling as claimed in claim 1, wherein a) one end of the socket joint (3) is provided with a ring structure (31 a) depending on the dia of the pipe to be joined having 4 or more bolting eye (32) and also having a resilient seating ring area (31) with diameter matching with that of the pipe to be joined so that minimum clearance is left which is sealed later on with the tapered portion of the resilient seating ring (2) when assembly is completed; b) the other end of the ball joint is provided with a ring structure (3 5 a) matching with the maximum dia of the ball joint so that it can easily enter and having 8 or more bolting eye (33) depending on the size of the ball as well as internal ‘O’ ring grove (34) and c) in between is the bell mouth area (35) of the socket joint which is the entry point of Ball Joint sliding area (54). 7) The underground pipe coupling as claimed in claim 1, wherein resilient sealing ring (2) a wide circular ring with one edge tapered which passes through the clearance between the pipe (8) and the socket joint (3) as well as the ball joint (5) and is the mating part with the grip cam mounting plate (1) and socket (3) as well as ball joint (5). 8) The underground pipe coupling as claimed in claim 1, wherein one end of the pipe (8) which is to be joined with socket joint (3) when inserted to the pipe admission path (13) of the grip cam mounting plate (1), the resilient sealing ring (2) is placed between the resilient ring pushing face (14) of the grip cam mounting plate and the socket joint (3), and on tightening the fasteners (15) linking the socket joint (5) and the grip cam mounting plate (1), the sealing ring (2) is pushed and gets closer to socket joint (5) and make it water tight. 9) The underground pipe coupling as claimed in claim 1, wherein one end of the pipe (8) which is to be joined with ball joint (5) when inserted to the pipe admission path (13) of the grip cam mounting plate (1), the resilient sealing ring (2) is placed between the resilient ring pushing face (14) of the grip cam mounting plate and the ball joint (5), and on tightening the fasteners (15) linking the ball joint (5) and the grip cam mounting plate (1), pushes the sealing ring (2) is pushed and gets closer to ball joint (5) and make it water tight. 10) The underground pipe coupling as claimed in claim 1, wherein the fasteners (15) are used to fasten and tighten between bolting eye (11) of the grip cam mounting plate (1) and a) bolting eye (32) of the socket joint for fastening grip cam mounting plate, thereby the tapered section of the resilience sealing (2) will get squeezed between the Grip cam mounting plate (1) and the resilient ring seat area of socket joint (31), there by sealing the gaps between Grip cam mounting plate (1), the socket joint (3) and the pipe (8) and make it watertight and b) bolting eye (52) of the ball joint, thereby the tapered section of the resilience sealing (2) will get squeezed between the Grip cam mounting plate (1) and the resilient ring seat area of the ball joint (51), there by sealing the gaps between Grip cam mounting plate (1), the ball joint (3) and the pipe (8) and make it watertight. 11) The underground pipe coupling as claimed in claim 1, wherein the grip cam arrangement in combination with single ball and socket joint takes care of the flexibility requirement arised out the stress caused by the environmental factors and is able to achieve mechanical flexibility of 30 to 60 degree, as against 3 to 6 degree of flexibility with the sealing ring used in conventional pipe joints. 12) The underground pipe coupling as claimed in claim 1, wherein ‘O’ ring (2) is positioned between the bell mouth area (35) of the socket joint (3), the entry point of ball Joint sliding area (54) enabling the sealing between the socket bell mouth (35) and the ball joint (5). 13) The underground pipe coupling as claimed in claim 1, wherein the ball joint back ring (4), a circular piece of steel ring with 8 or more number of bolting eye (41) matching to ring portion (35 a) of the socket joint and is having a curved profile, matching with the curved surface of the ball joint, so as to slide over the ball joint outer surface (54) and allows sliding of the ball joint (5) concentric with the socket joint (3), when the bolting eye (41) of the ball joint backing ring (4) and the bolting eye (33) of the socket joint are fastened using fasteners (15) after placing the ‘O’ ring (2), in the ‘O’ ring grove (34) of the socket joint. 14) The underground pipe coupling as claimed in claim 1, wherein the ball joint sliding area (54) is the entry point to socket Joint (3) bell mouth and when the ball joint (5) is coupled with socket joint (3), it is free to slide inside socket giving a mechanical flexibility up to 30 degree or above based on the size of the ball. 15) The underground pipe coupling as claimed in claim 1, wherein in place of grip cams (6), equal number of double grip cam assembly mechanism (64) with double grip cams (6 a) pivoted in the rectangular slot of a double grip cam mounting/holding block (70) by means of Grip cam shafts (67) are assembled in between a) the modified grip cam mounting plate (1 a), a circular ring structure with 3 to 4 numbers of Bolting eye (11) for fastening said modified grip cam mounting plate (1 a) with the Ball Joint (5) on one pipe end, the Socket Joint (3) on the other pipe end and threaded holes 4 pair of threaded hole (66 a) for assembling the double grip cam mounting/holding block (70) and b) the back plate (65), another circular ring structure consisting of sets of threaded holes (69 a), for assembling the double grip cam mounting/holding block (70). 16) The underground pipe coupling as claimed in claim 15, wherein the double grip cam (6 a) pivoted in the rectangular slot of the double grip cam mounting/holding block (70) is capable of rotating on an eccentric axis of the Grip cam shafts (67) of the double grip cam mounting/holding block (70) which is assembled in between the modified grip cam mounting plate (1 a) and the back plate (65) facilitating to locks the broken pipes to be joined together. 17) The underground pipe coupling as claimed in claim 15, wherein double grip cam mounting/holding block (70) is a solid steel block provided with a rectangular slot (71) to fix double grip cams (6 a) and is provided with: a) a threaded hole (68 a) for inserting grub screw (68) from top of the block for pilot loading the grip cams(6 a) on the pipe; b) another two threaded holes (67 a) on the flat side for fixing the grip cams (6 a) by means of cam shafts (67) on which cam (6 a) is free to rotate; and c) one threaded hole (69 a) on one end for fixing the back plate (65) and another two threaded holes (66 a) on the other end of said block for fixing the modified grip cam mounting plate (1 a) by means of respective threaded fasteners (69 and 66), so that the double grip cam (6 a) is pivoted in the slot of double grip cam mounting/holding block (70), in such a way that it is free to rotate in its own axis as per the pipe movement in leaner direction. 18) A method of assembling the underground pipe coupling for emergency repair during pipe breakage as claimed in claim 1, comprising the steps of: a) preparation of the damaged pipe for joining by cutting away the damaged part and preparing first segment as well as the second segment; b) insertion of ball joint (5), resilient sealing ring (2), grip cam mounting plate (1), and ball joint back ring(4) on the first segment of the pipe (8 a) to be joined in the same order; c) insertion of socket joint (3) fixed with ‘o’ ring (7), resilient sealing ring (2), and grip cam mounting plate (1), on the second segment of the pipe (8 b) to be joined in the same order; d) coupling of ball join (5) and socket joint (3); e) clamping the ball joint (5) to socket joint(3) by means of the ball joint back ring (4) and fastening by means of fasteners (15); f) fastening the grip cam mounting plate (1) with ball joint (5) by means of fasteners (15), with resilient sealing ring (2) in between for the first segment part (8 a) and tighten it to ensure sealing; g) fastening the grip cam mounting plate (1) with socket joint (5), by means of fasteners (15), with resilient sealing ring (2) in between for the second segment part (8 b) and tighten it to ensure sealing; h) locking the grip cam (6) of the respective grip cam mounting plate (1) both for the first segment part and the second segment part; and; i) wrapping the coupler with sealing tape having anti corrosion properties. 19) The method of assembling the underground pipe coupling for emergency repair during pipe breakage as claimed in claim 1, when double grip cams (6 a) are used, instead of the grip cam (6), said method comprising the steps of: a) preparation of the damaged pipe for joining by cutting away the damaged part and preparing first segment as well as the second segment; b) insertion of ball joint (5), resilient sealing ring (2), grip cam mounting plate (1 a) assembled with, and ball joint back ring(4) on the first segment of the pipe (8 a) to be joined in the same order; c) insertion of socket joint (3) fixed with ‘o’ ring (7), resilient sealing ring (2), and grip cam mounting plate (1 a), on the second segment of the pipe (8 b) to be joined in the same order; d) coupling of ball join (5) and socket joint (3); e) clamping the ball joint (5) to socket joint(3) by means of the ball joint back ring (4) and fastening by means of fasteners (15); f) fastening the grip cam mounting plate (1 a) with ball joint (5) by means of fasteners (15), with resilient sealing ring (2) in between for the first segment of the pipe part (8 a) and tighten it to ensure sealing; g) fastening the grip cam mounting plate (1 a) with socket joint (5), by means of fasteners (15), with resilient sealing ring (2) in between for the second segment of the pipe part (8 b) and tighten it to ensure sealing; h) assembling 4 nos of double grip cam assembly mechanism (64) having the double grip cam (6 a) in between the modified grip cam mounting plate (1 a) and back plate (65) by means of fasteners (66) and (69) i) locking the double grip cam (6 a) of the respective double grip cam assembly mechanism (64) both for the first segment of the pipe part and the second segment of the pipe part; and j) wrapping the coupler with sealing tape having anti corrosion properties. 20) The method of assembling the underground pipe coupling for emergency repair during pipe breakage as claimed in claim 19, wherein the method of assembling the double grip cam assembly mechanism (64) comprising the steps of: a) placing the double grip cam (6 a) in the Rectangular slot (71) provided in the double grip cam mounting/holding block (70); b) inserting the Cam shaft (67) through the holes (67 a) provided on the double grip cam mounting/holding block (70), and through the holes(6 b) in double grip cam (6 a) and finally locking the shaft using the Circlip (67 b); and c) inserting the Grub screw (68) for pilot loading of the grip cams (6 a) though the threaded holes (68 a) provided on the double grip cam mounting/holding block (70). 